1. Technical Field
The disclosure relates to a cooling apparatus for an internal combustion engine.
2. Description of Related Art
Japanese Patent Application Publication No. 2011-21482 describes a cooling apparatus for an automobile engine (internal combustion engine). In this cooling apparatus, a main circuit and a warm-up circuit are connected to the outlet side of a coolant jacket formed inside an engine body. The main circuit is provided with a radiator. The warm-up circuit allows a coolant flow to bypass the main circuit. This cooling apparatus includes a coolant pump and a thermostat. The coolant pump is operated in response to an operation of the engine. The thermostat is switched between a closed state where a coolant discharged from the coolant jacket is introduced into the warm-up circuit, and an open state where the coolant discharged from the coolant jacket is introduced into the main circuit, depending on the coolant temperature.
The thermostat is kept in the closed state during cold start of the engine. Thus, the coolant discharged from the coolant jacket is introduced into the warm-up circuit to bypass the radiator, so that the engine is promptly warmed up. Upon completion of warm-up of the engine, the thermostat is switched to the open state. Thus, the coolant discharged from the coolant jacket is introduced into the main circuit, and heat recovered from the engine body is released into the atmosphere by the radiator.
Some cooling apparatuses are provided with a coolant temperature sensor disposed at a position at the outlet side of the coolant jacket and upstream of the position at which the main circuit is connected to the coolant jacket, and control the engine (e.g., control the fuel injection amount) based on the coolant temperature detected by the coolant temperature sensor. After cold start of the engine, before the thermostat is switched to the open state, that is, before the thermostat makes switchover from the state where the coolant discharged from the coolant jacket flows through the warm-up circuit to the state where the coolant discharged from the coolant jacket flows through the main circuit, the engine stops and thus the coolant pump stops, and then the engine is restarted within a short period of time, in some cases.